This invention relates to a plasma collection bottle with an integral sample vial for taking a representative sample of contents of the bottle for analysis.
Blood plasma is obtained from donors by techniques that differ somewhat from donation of whole blood in a technique known as plasmapheresis. In a manual pheresis technique, a donation of several hundred milliliters of whole blood is withdrawn from the donor into a plastic bag. The blood donation is then separated in a centrifuge and the clear plasma is withdrawn and transferred to a "pooling bottle". The remaining fraction of blood containing the red cells is diluted with saline and reinjected into the donor. After a suitable lapse of time another donation of several hundred milliliters is withdrawn from the donor. Again, the sample is separated by a centrifuge and another portion of plasma is transferred to the pooling bottle. The remaining red cells are again diluted and reinjected into the donor.
Alternatively, the plasma is obtained by a technique referred to as autopheresis. Whereas, manual pheresis is a batch technique, autopheresis is continuous. Whole blood is withdrawn from the donor, a plasma fraction is separated continuously and the red cell fraction is reinjected continuously.
In either case the plasma is transferred to a pooling bottle which is typically a one-liter sealed plastic bottle made of medical grade ethylene-propylene copolymer. A similar bottle is used for either manual plasmapheresis or autopheresis. The only difference is that with autopheresis there is a single medical grade polyvinyl chloride (pvc) transfer tube for introducing plasma into the bottle, whereas, for manual pheresis there is a Y-connection near the top of the bottle and two transfer tubes are used for receiving the two batches of plasma.
A complication of manual pheresis is that there are occasions when plasma donations from more than one donor are inadvertently commingled in a single pooling bottle via two transfer tubes. If a sample is taken from only one of the transfer tubes, it cannot be representative of the plasma from both donors.
A second flexible pvc tube is connected to the top of the bottle and is closed with a sufficiently fine filter to permit air to vent from the bottle as it is filled and prevent microorganisms from entering the sterile bottle.
After the plasma is transferred to the pooling bottle, the transfer tube and the vent tube are heat sealed and severed so that the plasma is completely sealed inside the bottle and isolated from contamination. After collecting the plasma donations they are frozen and shipped to central facilities where large amounts of plasma from a broad variety of donors is commingled and processed for recovering valuable fractions used for a variety of medical purposes.
It is extremely important that any plasma that is contaminated be identified so that it is not commingled with usable plasma, since this could result in hazard to a large number of patients receiving fractions from the processed plasma. For example, it is important that the plasma be assayed for viral contamination such as HIV which could be life threatening. Samples of the plasma are therefore taken from each donation for laboratory analysis. Such analyses are performed in a central laboratory separate from the collection centers, and sometimes separate from the plasma processing facilities. The samples of plasma for analysis must therefore be carefully and accurately correlated with the plasma in the pooling bottle so that if contamination is identified, the plasma in the pooling bottle may be diverted from commingling with other plasma.
Current practice has been to mark a short heat-sealed length of the flexible transfer tube with indicia identical to that on the pooling bottle and ship the sealed transfer tube to a testing laboratory. There the transfer tube is cut and the plasma drained into a suitable test tube or other vial for analysis. This is not only inconvenient, but there is a possibility of extraneous contamination and a minor hazard to personnel where the transfer tubes are cut.
Through labeling errors, there may also be a risk of mixing up transfer tubes and losing correlation with the plasma in the pooling bottles. Furthermore, the sample of plasma in each transfer tube is representative only of a portion of the plasma transferred and is not necessarily representative of the plasma in the pooling bottle. This is particularly true of the manual pheresis technique where the sample in one of the transfer tubes is representative only of one of the batches of plasma commingled in the pooling bottle, and if there is an inadvertent pooling of plasma from two donors, serious errors may occur. The practice has been to use the first transfer tube for a sample. This, of course, is highly risky if plasma from more than one donor is transferred into the pooling bottle since the second transfer may be contaminated and would not be represented in the sample.
It is therefore desirable to provide a plasma collection and sampling system which provides samples representative of the contents of the pooling bottle and which has a high degree of reliability for accurate correlation between an analysis sample and the pooling bottle. It is desirable that the technique provided for obtaining a sample is convenient, safe, reliable, accurate and compatible with automated testing equipment.